Principle active metabolites of Pinus morrisonicola Hayata synergistically inhibit cell proliferation and autophagy to elevate apoptosis in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC), a common primary tumor of liver is a leading cause of cancer-associated deaths. Improving cellular apoptosis and enhancing autophagic clearance is been considered to improve treatment outcomes of HCC. Polyphenols from Pinus morrisonicola (Hayata) have shown various physiological and therapeutic benefits and the flavonoid chrysin is been known for their anticancer effects. However, the main bioactive principle and the mechanism underlying the antitumor activity of pine needle extract are not clear yet. In this study, the effects of ethanol extract from pine needle on HCC cells were determined. The results show that when compared with administration of chrysin alone, a fraction containing pinocembrin, chrysin, and tiliroside significantly reduced autophagy and increased apoptosis. The results also correlated with decrease in cell cycle regulators and the autophagic proteins like LC3-II. Collectively, the results imply the fraction containing pinocembrin, chrysin, and tiliroside as an ideal complementary medicine for an effective antitumor activity.